This invention relates generally to the art of automobile and truck tires and relates more particularly to a novel valve assembly therefor.
Within the trucking industry alone significant sums are expended for the sole purpose of maintaining vehicle tires at a safe operating pressure. Conventional valve assemblies permit sufficient leakage of pressurized fluid from pneumatic tires to make it mandatory to spend significant personnel time measuring and maintaining safe tire pressure. This problem is exacerbated by the tendency of maintenance personnel and mechanics in general to neglect replacement of end caps, which are adapted to seal the internal portion of the valve stems from exposure to atmosphere and environmental soil. With the absence of such end caps, road soil enters the conventional cores of such mechanisms to impair the normal operation thereof. The presence of environmental soil increases leakage through the valve assembly and further increases the expenses associated with the maintenance of appropriate presesures within truck tires.
Similar problems are associated with automobile tires, but not to the same extent experienced in the trucking industry. Various prior art valves and valve assemblies have attempted to overcome the problems associated with leakage through the valve stem assemblies.
One solution to this problem is disclosed in U.S. patent application Ser. No. 344,981 of Feb. 2, 1982 to Mr. John H. Zabel, Jr. the disclosure of which is hereby incorporated by a reference.
U.S. Pat. No. 1,956,981 to Crowley discloses a valve mechanism which attaches over an existing valve stem and has a sealing member which is an attempt to circumvent the problems associated with the failure to reattach end caps during normal maintenance. The mechanism disclosed in this patent however is still subject to fouling by road grime and soil.
U.S. Pat. No. 614,968 to Mohs discloses the use of a flexible sleeve with slits for the introduction and exhausting of pressurized fluid. Normally the high pressure side of the valve collapses the sleeve about a rod. If the rod is extracted from the valve assembly, the tube is expanded to permit the pressurized fluid to flow through slits and to exit the pneumatic tire.
U.S. Pat. No. 404,400 to DeWolfe discloses a valve for a bicyle tire comprising a central plug having an axial orifice communicating with a circumferential groove for the purpose of inflating the bicyle tire through the orifice groove. The tire is prevented from deflating by the collapse around the circumferential groove of a rubber sleeve.
Another patent showing the use of a rubber sleeve about a central core having an orifice therethrough in U.S. Pat. No. 1,469,966 to M. C. Schweinert. French Pat. No. 596,081 to Medini also discloses a sleeve structure within a valve.
U.S. Pat. No. 2,778,374 to Boyer discloses a more conventional valve for use on large tires.
While the aforementioned prior art mechanisms possess unique advantages, there has been no commercially available tire valve, particularly to the trucking industry, which remedies the problems discussed above.